P0616 - Validation of Detecting Rectal Hypersensitivity According to London and ANMS/ESNM Protocols Using the Office-Based, Point-of-Care Rectal Expulsion Device (RED) in Patients With Chronic Constipation: Clinical Trial
Eric Shah, MD, MBA, FACG1, Pablo Martinez-Camblor, PhD2, William D. Chey, MD, FACG1 1University of Michigan, Ann Arbor, MI; 2Dartmouth Hitchcock Medical Center, Lebanon, NH
Introduction: Fecal urgency is common among constipated patients and can be treated with pelvic floor physical therapy to optimize patient perception of bowel control, yet access to laboratory-based testing is limited. We aimed to evaluate the diagnostic accuracy of an office-based, point-of-care test called RED to identify rectal hypersensitivity among patients with chronic constipation in general gastroenterology.
Methods: This was an analysis on pre-specified exploratory outcomes of a clinical trial prospectively enrolling 60 patients referred to general gastroenterology who met Rome IV functional constipation criteria between May 2020 and June 2021 (mean age 46.6 years, 93.3% women). All patients underwent RED as a qualitative test followed by volumetric, laboratory-based ramp balloon distention according to the London protocol. Rectal hypersensitivity was defined on RED according the patient reporting an urgency to defecate with the inserted device. The gold standard for rectal hypersensitivity was defined on ramp balloon distention as having at least two of the three volumes for "first sensation", "urge to defecate", or "maximum tolerated” below their optimized volumetric thresholds consistent with the London protocol. Rectal hypersensitivity was alternatively defined on the urge to defecate question alone, as a finding that ties to rectal sensation training detailed in the ANMS/ESNM protocol. Diagnostic accuracy of RED to detect rectal hypersensitivity was measured using the area under the receiving operating characteristic curve (AUC). 1 patient did not undergo rectal sensation testing due to suspected anal fissure, and 5 patients did not report sensory thresholds using standard scripted scenarios.
Results: Rectal hypersensitivity was identified on RED in 31.0% of patients (18 of 58 patients), compared to 29.8% (17/54) with ramp balloon distention according to the London consensus. The AUC to detect rectal hypersensitivity according to the London consensus was 0.71 (95% CI 0.57 to 0.85) with a sensitivity of 65% and specificity of 65%. RED has a sensitivity of 85% and specificity of 32% to detect rectal hypersensitivity according to the urge to defecate question that ties to rectal sensory training according to the ANMS/ESNM protocol.
Discussion: RED offers the opportunity to qualitatively screen for rectal hypersensitivity at point-of-care based on sensitivity to detect urge-to-defecate, and to thereby improve access to anorectal function testing beyond tertiary motility centers.
Eric Shah, MD, MBA, FACG1, Pablo Martinez-Camblor, PhD2, William D. Chey, MD, FACG1. P0616 - Validation of Detecting Rectal Hypersensitivity According to London and ANMS/ESNM Protocols Using the Office-Based, Point-of-Care Rectal Expulsion Device (RED) in Patients With Chronic Constipation: Clinical Trial, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.
